Granulomatosis with polyangiitis presenting as Henoch-Schönlein purpura in children.

Granulomatosis with polyangiitis (GPA), formerly known as Wegener granulomatosis, in children is an uncommon chronic organ- and life-threatening systemic vasculitis that may share at time of initial presentation a number of clinical features in common with Henoch-Schönlein purpura (HSP), a very common and comparatively benign form of childhood vasculitis. Diagnosis of GPA requires a high index of suspicion, and antineutrophil cytoplasmic antibody tests along with tissue biopsy are helpful tools for diagnosis. We report 2 patients with GPA masqueraded as HSP at time of initial presentation. Both patients presented with nonthrombocytopenic purpura on lower extremities, in addition to abdominal pain, and/or microscopic hematuria and fulfilled both the American College of Rheumatology and the Pediatric Rheumatology European Society classification criteria for HSP. Both patients eventually developed significant renal and pulmonary disease and were diagnosed with GPA. We aim to raise awareness of such atypical presentations of GPA to avoid delayed management.